RewriteEngine not allowed here

First of all, thanks for your help, i've been looking for an answer to my problem but i couldn't find one, i'v tried all the solutions but it didn't work for me...
Here is my problem:
I have Installed Ispconfig 3, everything is working except the URL rewriting using Wordpress, when i check the logs of the web site i can see the error:RewriteEngine not allowed hereThe code of the htaccess is:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

The code of my conf file is :
<Directory /var/www/fnaire.info>
AllowOverride all
Order Deny,Allow
allow from all
</Directory>

i just tried but it didn't work...it adds the code on my fnaire.info.vhost file (apache restarted) and i keep getting the 500 error

Click to expand...

Alright, leave the code in the apache directive that I mentioned in my last post.
In your .htaccess file, comment out "RewriteBase /", this is only used if your wordpress installation is in another directory other then root. So basically comment it out if your WP is installed in /var/www/fnaire.info/web/.

Also, comment out this in your .htaccess file:
Options +FollowSymLinks

do you think that the problem is coming from my php.ini?
i also have a worning everytime i restart my apache:
[warn] NameVirtualHost 87.98.170.131:80 has no VirtualHosts
[warn] NameVirtualHost 87.98.170.131:443 has no VirtualHosts

I had similar issues trying to set rewrites in Joomla up, heres how I fixed it:

gedit /etc/apache2/sites-available/www.domain.com.vhost

(lines 1 to 5)

Code:

<Directory /var/www/www.domain.com>
AllowOverride All
Order Allow,Deny
Allow from all
</Directory>

(lines 23-34)

Code:

<Directory /var/www/www.domain.com/web>
Options Indexes FollowSymLinks Includes ExecCGI
AllowOverride All
Order allow,deny
Allow from all
</Directory>
<Directory /var/www/clients/client1/web1/web>
Options Indexes FollowSymLinks Includes ExecCGI
AllowOverride All
Order allow,deny
Allow from all
</Directory>